TWI396464B - Organic electroluminescence display device and manufacturing method thereof - Google Patents

Description

Organic electroluminescence display device and manufacturing method thereof

The present invention relates to an organic electroluminescence display device, and more particularly to an organic electroluminescence display device having an improved ability to isolate moisture and a method of fabricating the same.

Compared with conventional displays, such as cathode ray tube displays (CRTs) and liquid crystal displays (LCDs), organic electroluminescent display devices have advantages of better chroma, viewing angle, brightness, and small volume, so that organic electroluminescent display devices The demand is also growing. Since the components in the organic electroluminescence display device are extremely susceptible to external moisture, such as oxidation of the electrodes, the life of the organic electroluminescent display device is reduced. Therefore, for fabricating an organic electroluminescence display device, the package structure of the organic electroluminescence display device and its fabrication are very critical steps.

In Fig. 1, a conventional organic electroluminescence display device is shown. In the above organic electroluminescent display device, the first electrode 12 is formed on the first substrate 10, and then the organic electroluminescent layer 14 and the second electrode 16 are sequentially formed over the first electrode 12, and then covered with a protective layer. 18 is disposed on the second electrode 16 and correspondingly disposed on the first substrate 10 above the first substrate 10. Since only one protective layer is formed, the effect of isolating moisture is poor, and on the other hand, if the thickness of the protective layer is increased, the overall thickness of the organic electroluminescent display device is increased.

Therefore, there is a need for an organic power that has the ability to enhance the ability to isolate moisture. An electroluminescence display device and a method of fabricating the same.

In view of the above, an object of the present invention is to provide an organic electroluminescence display device. The organic electroluminescent display device includes a first substrate having at least one thin film transistor; a light emitting unit formed on the first substrate; a first protective layer formed over the light emitting unit; a second a protective layer formed on the first protective layer; and a third protective layer formed on the second protective layer and contacting the first protective layer. The organic electroluminescent display device further includes a second substrate sealed on the first substrate to form the light emitting unit between the first substrate and the second substrate.

In the above organic electroluminescent display device, the top surface area of the second protective layer in contact with the third protective layer is greater than or equal to the bottom surface area of the second protective layer in contact with the first protective layer.

In the above organic electroluminescent display device, the distance between the top edge of the second protective layer and the third protective layer is greater than or equal to the distance between the second protective layer and the bottom edge of the first protective layer.

Another object of the present invention is to provide a method of fabricating an organic electroluminescence display device. The method for fabricating the organic electroluminescent display device includes: providing a first substrate having a thin film transistor; then forming a light emitting unit on the first substrate and electrically connecting the thin film transistor; and then forming a a first protective layer on the light emitting unit; then, forming a second protective layer over the first protective layer; and forming a The third protective layer is on the second protective layer and contacts the first protective layer. The method for fabricating the organic electroluminescent display device further includes sealing a second substrate over the first substrate to form the light emitting unit between the first substrate and the second substrate. In the above method for fabricating an organic electroluminescence display device, the formation of the second protective layer is performed by inkjet printing or screen printing.

According to the organic electroluminescence display device produced by the present invention, a first protective layer containing an inorganic material, a second protective layer containing an organic material, and a third protective layer containing an inorganic material are formed above the light emitting unit for effective isolation Moisture invades the light-emitting unit, thereby reducing the oxidation of the electrode of the light-emitting unit caused by moisture. Furthermore, the second protective layer is formed only above the light-emitting unit, so that no waste of material is caused, and the manufacturing cost is increased, and the second protective layer containing the organic material also reduces the first protection including the inorganic material. The stress between the layer and the third protective layer. In addition, since the second protective layer is formed only on the single light, the ability to isolate moisture can be effectively increased without increasing the thickness of the display device, thereby increasing the service life of the display device.

Next, a preferred embodiment of the present invention and a method of fabricating the same will be described in detail. However, it will be appreciated that the present invention provides many inventive concepts that can be implemented in a wide variety of applications. The embodiments used for the description are merely illustrative of specific embodiments of the present invention and are not intended to limit the scope of the invention.

In Figs. 2A to 2H, there are shown cross-sectional views showing the formation of an organic electroluminescent display device according to the first embodiment of the present invention. In the first embodiment of the present invention, the color filter layer in the organic electroluminescence display device and the thin film transistor (TFT) as a switch may be disposed on the same substrate. That is to say, the color filter layer in the first embodiment can be formed on the same substrate as the process of the thin film transistor.

As shown in FIG. 2A, a color filter layer 204 is formed on a first substrate 200 having a plurality of thin film transistors 202. The first substrate 200 may preferably be a transparent material such as glass or plastic, and may of course be a transparent material having flexibility.

The thin film transistor 202 includes a gate 2021, a source 2025, and a drain 2023. The gate 2021 is formed on the first substrate 200, and the source 2025 and the drain 2023 are respectively formed above the gate 2021. A thin film transistor 202 that can function as a switch is constructed. The manner of forming the above-mentioned gate, source and drain may be a usual manner and will not be described herein.

As shown in FIG. 2A, a dielectric layer 203 is formed on the first substrate 200 and covers the thin film transistor 202 to protect and isolate the thin film transistor 202. In a preferred embodiment, the dielectric layer 203 may be formed by, for example, low temperature chemical vapor deposition (LTCVD) or plasma enhanced chemical vapor deposition (PECVD). ) or low pressure chemical vapor deposition (low pressure chemical vapor deposition; The chemical vapor deposition method of LPCVD), and preferably the dielectric layer 203 may be tantalum oxide, tantalum nitride or other material which can serve as a dielectric layer.

Next, a color filter layer 204 is formed on the dielectric layer 203 of the first substrate 200. In a preferred embodiment, the color filter layer 204 is disposed above the substrate 200 where the thin film transistor 202 is not formed, that is, the thin film transistor 202 is not disposed under the color filter layer 204. Further, the thin film transistor 202 can also be used as a light shielding layer of, for example, a black matrix (BM). Therefore, the organic electroluminescence display device according to the first embodiment of the present invention can reduce the cost of materials without forming a light shielding layer.

In a preferred embodiment, the color filter layer 204 is formed by using an ink-jet printing (IJP) method to include a red color pigment and a green color pigment. A color filter layer 204 of blue pigment is sprayed onto the first substrate 200, and then a baking step is performed to form the color filter layer 204. The color filter layer 204 may preferably be an organic color resist material or other material that can be used as a color filter layer.

In FIG. 2B, an overcoat layer 206 is overlaid on the first substrate 200 and covers the color filter layer 204 and the thin film transistor 202 to planarize the surface of the first substrate 200. The flat layer 206 may preferably be a photosensitive material and formed by, for example, spin coating. Next, a lithography and etching process is performed to pattern the planar layer 206 to form a contact hole 207 and expose the upper surface of the drain 2023 of the thin film transistor 202.

After the contact hole 207 is completed, the first electrode 208 is formed. The flat layer 206 extends into the contact hole 207 to electrically connect the drain 2023 of the thin film transistor 202, as shown in FIG. 2B. In a preferred embodiment, the first electrode 208 is formed by, for example, sputtering to form a transparent conductive layer such as Indium Tin Oxide (ITO), and the lithography and etching process is performed. The conductive layer is patterned to form a first electrode 208 that substantially corresponds to above the color filter layer 204 on the first substrate 200. The first electrode 208 can be used as an anode for subsequently forming a light-emitting unit, and thus can also be referred to as an anode electrode.

As shown in FIG. 2C, a pixel define layer (PDL) 210 having a plurality of openings 209 is formed on the first substrate 200, and each of the openings 209 exposes a portion of the first electrode 208 to form a pixel. Pixel area 212. In a preferred embodiment, a pixel defining layer 210, such as a photosensitive material, is formed on the first substrate 200 and covers the first electrode 208 by, for example, spin coating. Next, the pixel defining layer 210 is patterned to form a predetermined opening 209 to expose the surface of the first electrode 208.

It should be noted that the pixel region 212 is substantially correspondingly formed above the first electrode 208 and the color filter layer 204. Moreover, the distance between the top edges of the pixel regions 212 is greater than or equal to the distance between the pixel regions 212 and the bottom edges of the first electrodes 208.

As shown in FIG. 2D, an organic electroluminescent layer 214 is formed on the first electrode 208 in the pixel region 212 to provide a display device light source. In an embodiment, the organic electroluminescent layer 214 may be vacuum evaporated (vacuum) The evaporation method is completed, and the organic electroluminescent layer 214 may be a stacked layer including a blue emitting layer, a red emitting layer, and a green emitting layer, or The blue luminescent layer is doped with a yellow luminescent material (or red luminescent material) to provide, for example, a white light source to the display device. In another embodiment, before the formation of the organic electroluminescent layer 214, a hole injection layer and a hole transport layer may be sequentially formed over the first electrode 208. Next, after the organic electroluminescent layer 214 is formed, an electron transport layer and an electron injection layer are sequentially formed over the organic electroluminescent layer 214.

In FIG. 2E, a second electrode 216 is conformally formed on the first substrate 200 and covers the pixel defining layer 210 and the organic electroluminescent layer 214. The second electrode 216 and the organic electroluminescent layer 214 and the first electrode 208 in the pixel region 212 constitute a light emitting unit 217, and the second electrode 216 can serve as a cathode electrode of the light emitting unit 217. In a preferred embodiment, the second electrode 216 may be formed by, for example, sputtering, electron beam evaporation, or thermal evaporation, and may preferably be aluminum. , aluminum-lithium alloys or magnesium-sliver alloys.

It should be noted that the light-emitting unit 217 including the first electrode 208, the organic electroluminescent layer 214 and the second electrode 216 in the pixel region 212 is correspondingly disposed above the color filter layer 204. When the current passes through When the light unit 217 is used, the electrons provided by the second electrode 216 and the holes provided by the first electrode 208 are combined in the organic electroluminescent layer 214, so that the organic electroluminescent layer 214 emits light, and the light passes through the first An electrode 208, a color filter layer 204 and the first substrate 200 are outside the display device.

Next, a first protective layer 218 is formed conformally on the second electrode 216 as shown in FIG. 2F. In a preferred embodiment, the first protective layer 218 may be formed by vacuum evaporation, sputtering or plasma enhanced chemical vapor deposition. ;PECVD). The first protective layer 218 preferably has a thickness ranging from 0.1 um to 0.5 um.

In a preferred embodiment, the first protective layer 218 may preferably be an inorganic material such as metal oxide, metal nitride, metal carbide, or metal oxynitride. ) and its combination. The oxidized metal may preferably be silicon oxide (SiOx), aluminum oxide (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), indium oxide (In ₂ O ₃ ), oxidation. Tin oxide (SnO ₂ ), indium tin oxide (ITO), and combinations thereof. The above metal nitride is preferably, for example, aluminum nitride (AlN), silicon nitride (SiNx), or a combination thereof. The above carbonized metal is preferably, for example, silicon carbide (SiC). Further, the above metal oxynitride may preferably be silicon oxynitride (SiON).

As shown in FIG. 2F, a second protective layer 220 is formed on the above The first protective layer 218 above the light unit 217, and the recess 219 above the light emitting unit 217 can accommodate the second protective layer 220 therein. In a preferred embodiment, the second protective layer 220 may be formed by first spraying the second protective layer 220 over the light emitting unit 217 by inkjet printing (IJP). On layer 218. It is noted that since the second protective layer 220 is received in the recess 219, the upper surface of the second protective layer 220 and the upper surface of the first protective layer 218 form a substantially planar surface.

Then, a curing step such as thermal curing or photo curing is performed, wherein the curing step is determined by the material of the second protective layer 220. For example, when the second protective layer 220 is a thermal resin, the curing step can be performed by a heat treatment step. Two protective layers 220. When the second protective layer 220 is a photosensitive material, the second protective layer 220 can be cured by ultraviolet light or visible light. In a preferred embodiment, the viscosity of the second protective layer 220 before the curing step is preferably between 1 kPa and 1000 kPa. In another embodiment, the second protective layer 220 may be directly printed on the first protective layer 218 in the recess 219 above the light emitting unit 217 by means of screen printing.

In a preferred embodiment, the second protective layer 220 may be an organic material, such as an epoxidized or thermally curable type of acrylic curable polymer of a photo curable type material. material. It should be noted that the distance of the top edge of the second protective layer 220 is greater than or equal to the distance between the second protective 220 and the bottom edge of the first protective layer 218. Since the second protection 220 is formed in the light The first protective layer 218 over the cell such that the top surfaces of the second protective layer 220 and the first protective layer 218 form a substantially planar surface.

In the 2GG, the third protective layer 222 is formed on the first substrate 200 and contacts the surface of the first protective layer 218. In a preferred embodiment, the third protective layer 222 may be formed by vacuum evaporation, sputtering or plasma enhanced chemical vapor deposition to form a third protective layer 222 on the first protective layer 218 and On the surface of the second protective layer 220. The third protective layer 222 preferably has a thickness ranging from about 0.1 um to about 0.5 um. The material forming the third protective layer 222 may be a material similar to that of the first protective layer 218, and thus will not be described again.

It should be noted that the top surface of the second protective layer 220 in contact with the third protective layer 222 is greater than or equal to the bottom surface area of the second protective layer 220 in contact with the first protective layer 218. That is, the distance between the top edge of the second protective layer 220 in contact with the third protective layer 222 (such as the distance b in FIG. 2G) is greater than or equal to the bottom of the second protective layer 220 in contact with the first protective layer 218. The distance between the edges (such as the distance a in Figure 2G) is shown in Figure 2G. Furthermore, the distance between the bottom edge of the second protective layer 220 in contact with the first protective layer 218 is greater than or equal to the distance between the bottom edge of the organic electroluminescent layer 214 and the first electrode 208 (as in FIG. 2G). The distance c), that is, the bottom width of the second protective layer 220 (such as the distance a in the 2G diagram) is greater than or equal to the bottom width of the organic electroluminescent layer 214 (such as the distance c in the 2G diagram), As shown in Figure 2G.

It can be understood that the first protective layer 218, the second protective layer 220, and the third protective layer 222 in the embodiment may preferably be transparent materials. The second electrode 216 can also be a transparent conductive material.

Then, a second substrate 228 is correspondingly disposed on the first substrate 200 with a sealant 226 in a vacuum or filled with nitrogen or argon, and a buffer layer 224 is formed on the first substrate 200 and the second substrate. Between 228, the organic electroluminescent display device according to the first embodiment of the present invention is completed, as shown in FIG. 2H. The second substrate 228 may be a material similar to the first substrate 200 or a plastic film that can be used as a package board, such as a plastic film having a waterproof layer formed on the surface. The sealant 226 described above may be an adhesive such as an epoxy group.

When a current passes through the light emitting unit, the electrons provided by the second electrode (also referred to as the cathode) and the holes provided by the first electrode (also referred to as the anode) are combined in the organic electroluminescent layer, so that the organic electroluminescent layer Light is emitted, and the light passes through the first electrode, the color filter layer, and the first substrate to the outside of the display device, as indicated by the arrow in FIG. 2H.

An organic electroluminescence display device fabricated according to the first embodiment of the present invention has a first protective layer 218 containing an inorganic material, a second protective layer 220 containing an organic material, and a third protective layer containing an inorganic material formed above the light emitting unit. The layer 222 injects moisture into the light-emitting unit with effective isolation, thereby reducing the oxidation of the electrode of the light-emitting unit caused by moisture, and the second protective layer containing the organic material also reduces the first protective layer and the third layer containing the inorganic material. The stress between the protective layers. Furthermore, since the second protective layer 220 is formed only above the light-emitting unit, the cost of fabrication can also be reduced. In addition, since the second protective layer 220 is formed only above the light emitting unit in the pixel region, the thickness of the display device can be increased without increasing the thickness of the display device. The utility model effectively increases the ability to isolate moisture, thereby increasing the service life of the display device.

3A to 3E are cross-sectional views showing the formation of an organic electroluminescence display device according to a second embodiment of the present invention. In the second embodiment of the present invention, the color filter layer in the organic electroluminescence display device and the thin film transistor system as a switch are respectively disposed on different substrates.

In FIG. 3A, a reflective layer 306 is formed on the first substrate 300 having a plurality of thin film transistors 302, and the reflective layer 306 is located over portions of the first substrate 300 where the thin film transistor 302 is not formed. Before forming the reflective layer 306, a dielectric layer 303 and a planarization layer 304 are sequentially formed on the first substrate, and the thin film electrical devices 302 are covered. In addition, the thin film transistor 302, the dielectric layer 303, and the flat layer 304 above the first substrate 300 may be formed and formed similarly to the thin film transistor, the dielectric layer, and the flat layer of the first embodiment. In a preferred embodiment, the reflective layer 306 is formed by forming a metal layer such as aluminum on the flat layer 304 above the first substrate 300 by, for example, sputtering or evaporation. Next, the metal layer is patterned to form a reflective layer 306 over a portion of the first substrate 300 where the thin film transistor 302 is not formed.

As shown in FIG. 3A, a first electrode 308 is formed on the reflective layer 306, and is electrically connected to the drain of the thin film transistor 302 through the contact hole 307. In a preferred embodiment, the first electrode 308 is formed by first shielding a reflective layer 306 and a portion of the planarization layer 304 by using a patterned photoresist layer (not shown), and then removing a portion of the planarization layer 304 and Dielectric layer 303, to form a contact hole exposing the drain of the thin film transistor 302. Thereafter, after removing the patterned photoresist layer, a transparent conductive layer such as indium tin oxide is formed on the planar layer 304, and the reflective layer 306 is covered, and then the transparent conductive layer is patterned such that the first electrode 308 is formed on the reflective layer. 306, and electrically connected to the drain of the thin film crystal 302 through the contact hole. The material and formation manner of the first electrode 308 may be similar to the first electrode in the first embodiment, wherein the first electrode 308 may also serve as an anode of the subsequently formed light emitting unit.

In FIG. 3B, a pixel defining layer 310 having an opening is formed on the first substrate 300, and the upper opening exposes the first electrode 308 over the reflective layer 306 to form a pixel region 312. In a preferred embodiment, the distance of the top edge of the pixel region 312 is greater than or equal to the distance of the pixel region 312 from the bottom edge of the first electrode 308. The material and formation method of the pixel defining layer 310 described above may be similar to the pixel defining layer in the first embodiment, and thus will not be described again.

As shown in FIG. 3C, an organic electroluminescent layer 314 is formed in the pixel region 312, and then a second electrode 316 is overlying the organic electroluminescent layer 314 and the pixel defining layer 310. The first electrode 308, the organic electroluminescent layer 314 and the second electrode 316 in the pixel region 312 constitute a light emitting unit 317, wherein the first electrode 308 and the second electrode 316 respectively serve as an anode and a cathode of the light emitting unit 317. The material and formation method of the organic electroluminescent layer 314 and the second electrode 316 may be similar to those of the organic electroluminescent layer and the second electrode in the first embodiment.

Next, a first protective layer 318 is formed on the second electrode 316, and then a second protective layer 320 is formed on the first protective layer 318 above the light emitting unit 317, as shown in FIG. 3D. In a preferred embodiment, a first protective layer 318, such as an inorganic material, may be formed on the second electrode 316 by vacuum evaporation, sputtering, or plasma enhanced chemical vapor deposition, and the first protection may be performed. The material of the layer 316 may be similar to the material of the first protective layer in the first embodiment. The first protective layer 318 preferably has a thickness ranging from 0.1 um to 0.5 um.

In a preferred embodiment, the second protective layer 320 is formed of, for example, an organic material. The second protective layer 320 may be sprayed on the light emitting unit 317 by inkjet printing (IJP). Above the first protective layer 318. Next, a curing step such as thermal curing or photocuring is performed to form the second protective layer 320 in the recess 319 above the light emitting unit 317, wherein the curing step is determined by the material of the second protective layer 320, for example, the second protection When the layer 320 is a thermal resin, the second protective layer 320 may be cured by a heat treatment step. When the second protective layer 320 is, for example, a photosensitive material, the second protective layer 320 can be cured by ultraviolet light or visible light. In a preferred embodiment, the viscosity of the second protective layer 320 before the curing step is preferably between 1 kPa and 1000 kPa. In another embodiment, the second protective layer 320 may be directly printed on the first protective layer 318 in the recess 319 above the light emitting unit 317 by means of screen printing. The second protective layer 320 is received in the recess 319. It is worth noting that since the second protective layer 320 is housed in the recess 319, The upper surface of the second protective layer 320 and the upper surface of the first protective layer 318 are substantially formed into a plane. The material of the second protective layer 320 is preferably similar to that of the second protective layer in the first embodiment, and therefore will not be described herein.

In FIG. 3E, a third protective layer 322, such as an inorganic material, is formed on the first substrate 300 and contacts the surfaces of the first protective layer 318 and the second protective layer 320. In a preferred embodiment, the third protective layer 322 preferably has a thickness ranging from about 0.1 um to about 0.5 um. The material and formation manner of the third protective layer 322 may be similar to the material and formation of the third protective layer in the first embodiment.

It should be noted that the top surface of the second protective layer 320 in contact with the third protective layer 322 is greater than or equal to the bottom surface area of the second protective layer 320 in contact with the first protective layer 318. That is, the distance between the top edge of the second protective layer 320 and the third protective layer 322 (such as the distance b in FIG. 3E) is greater than or equal to the bottom of the second protective layer 320 and the first protective layer 318. The distance between the edges (such as the distance a in Figure 3E) is shown in Figure 3E. Moreover, the distance between the bottom edge of the second protective layer 320 and the first protective layer 318 is greater than or equal to the distance between the bottom edge of the organic electroluminescent layer 314 and the first electrode 308 (as in FIG. 3E). The distance c), that is, the bottom width of the second protective layer 320 (such as the distance a in FIG. 3E) is greater than or equal to the bottom width of the organic electroluminescent layer 314 (as in the distance c in FIG. 3E), As shown in Figure 3E.

Next, a second substrate having a color filter layer is correspondingly disposed on the first substrate in a vacuum or a place filled with nitrogen or argon. 300, and a buffer layer is formed between the first substrate 300 and the second substrate to complete the organic electroluminescent display device according to the second embodiment of the present invention. The second substrate may be a material similar to the first substrate 300 or a plastic film having a waterproof layer formed on the surface. The above sealant may be an adhesive such as an epoxy group. The color filter layer is isolated by a light shielding layer and correspondingly disposed above the light emitting unit in the pixel region. The material and formation method of the color filter layer may be similar to the material and formation method of the color filter layer in the first embodiment, and may be any conventional manner and material for forming a color filter layer.

When the current passes through the light emitting unit, the electrons provided by the second electrode (cathode) and the holes provided by the first electrode (anode) are combined in the organic electroluminescent layer, so that the organic electroluminescent layer emits light, and the light will be The second electrode 316, the color filter layer and the second substrate are passed through the display device. However, the light that partially passes through the first electrode is also reflected by the reflective layer, and then passes through the above path to the outside of the display device.

An organic electroluminescence display device fabricated according to a second embodiment of the present invention, wherein a first protective layer containing an inorganic material, a second protective layer containing an organic material, and a third protective layer containing an inorganic material are formed over the light emitting unit Injecting moisture into the light-emitting unit with effective isolation, thereby reducing the oxidation of the electrode of the light-emitting unit caused by moisture, and the second protective layer containing the organic material also reduces the first protective layer and the third protective layer containing the inorganic material. The stress between. Moreover, the second protective layer is formed only above the light emitting unit, so that no waste of material is caused, and the manufacturing cost is increased. In addition, since the second guarantee is formed only in the pixel area The protective layer, therefore, can effectively increase the ability to isolate moisture without increasing the thickness of the display device, thereby increasing the service life of the display device.

It should be noted that the first protective layer, the second protective layer and the third protective layer in the second embodiment may be made of a transparent material, and the second electrode may preferably be a transparent conductive material.

Figure 4 is a cross-sectional view showing an organic electroluminescence display device of a third embodiment of the present invention. The maximum difference between this embodiment and the second embodiment is that a color photoresist material is used as the second protective layer. Therefore, similar components and steps can be referred to the foregoing, and are not described herein.

In FIG. 4, after the fabrication of the light-emitting unit 417 including the first electrode 410, the organic electroluminescent layer 414, and the second electrode 416 is completed, a first protective layer 418 is formed over the second electrode 416. The forming manner and material of the first protective layer 418 may be similar to the above embodiment. Thereafter, a second protective layer 420 of an organic color photoresist material is formed over the light emitting unit 417 to serve as a color filter layer. The manner in which the second protective layer 420 is formed may of course be the same as the inkjet printing or screen printing in the above embodiment.

After the second protective layer 420 is formed, a third protective layer 422 is overlaid over the second protective layer 420, and the third protective layer 422 is in direct contact with the first protective layer 418. Finally, the second substrate 428 is sealed over the first substrate 400 by the encapsulant 426, and the buffer layer 424 is filled between the first substrate 400 and the second substrate 428, as shown in FIG. It should be noted that in this embodiment, the upper surface of the second substrate 428 can be Therefore, it is not necessary to separately form a color filter layer and a light shielding layer. Therefore, in the third embodiment, not only the process steps can be reduced, but also the use cost of the material can be reduced. Furthermore, since the second protective layer 420 is an organic photoresist material, the stress between the first protective layer and the third protective layer containing the inorganic material can be reduced. Similarly, the second protective layer in the first embodiment may also use an organic color photoresist material as a protective layer to reduce the manufacturing cost. Although not disclosed in the present specification, it is to be understood that those skilled in the art can devise many variations, which are still within the scope of the invention.

Although the present invention has been disclosed in the above preferred embodiments, it is not intended to limit the invention, and it is to be understood that the present invention may be modified and retouched without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

10‧‧‧First substrate

12‧‧‧First electrode

14‧‧‧Organic electroluminescent layer

16‧‧‧second electrode

18‧‧‧Protective layer

20‧‧‧second substrate

200‧‧‧First substrate

202‧‧‧film transistor

2021‧‧‧ gate

2023‧‧‧汲polar

2025‧‧‧ source

203‧‧‧ dielectric layer

204‧‧‧Color filter layer

206‧‧‧flat layer

207‧‧‧Contact hole

208‧‧‧first electrode

209‧‧‧ openings

210‧‧‧ pixel definition layer

212‧‧‧ pixel area

214‧‧‧Organic electroluminescent layer

216‧‧‧second electrode

217‧‧‧Lighting unit

218‧‧‧ first protective layer

219‧‧‧ Groove

220‧‧‧Second protective layer

222‧‧‧ third protective layer

224‧‧‧buffer layer

226‧‧‧Packing

228‧‧‧second substrate

300‧‧‧First substrate

302‧‧‧film transistor

303‧‧‧ dielectric layer

304‧‧‧flat layer

306‧‧‧reflective layer

307‧‧‧Contact hole

308‧‧‧First electrode

309‧‧‧ openings

310‧‧‧ pixel definition layer

312‧‧‧ pixel area

314‧‧‧Organic electroluminescent layer

316‧‧‧second electrode

317‧‧‧Lighting unit

318‧‧‧ first protective layer

319‧‧‧ Groove

320‧‧‧Second protective layer

322‧‧‧ third protective layer

400‧‧‧First substrate

410‧‧‧First electrode

414‧‧‧Organic electroluminescent layer

416‧‧‧second electrode

417‧‧‧Lighting unit

418‧‧‧First protective layer

420‧‧‧Second protective layer

422‧‧‧ third protective layer

424‧‧‧buffer layer

428‧‧‧second substrate

1 is a view showing a conventional organic electroluminescence display device; FIGS. 2A to 2H are cross-sectional views showing a method of fabricating an organic electroluminescence display device according to a first embodiment of the present invention; FIGS. 3A to 3E are diagrams showing A cross-sectional view showing a method of fabricating an organic electroluminescence display device according to a second embodiment of the present invention; and a fourth view showing a cross-sectional view of an organic electroluminescence display device according to a third embodiment of the present invention.

200‧‧‧First substrate

202‧‧‧film transistor

208‧‧‧first electrode

214‧‧‧Organic electroluminescent layer

216‧‧‧second electrode

218‧‧‧ first protective layer

220‧‧‧Second protective layer

222‧‧‧ third protective layer

224‧‧‧buffer layer

226‧‧‧Packing

228‧‧‧second substrate

Claims (17)

A method for fabricating an organic electroluminescent display device, comprising: providing a first substrate having at least one thin film transistor; forming an illumination unit on the first substrate, and electrically connecting the thin film transistor; forming a first a protective layer is disposed on the light emitting unit; a second protective layer is formed on the first protective layer, wherein the first protective layer has a recess above the light emitting unit, and the second protective layer is disposed on the concave layer The upper surface of the second protective layer is coplanar with the upper surface of the first protective layer; and a third protective layer is formed on the second protective layer and contacts the first protective layer, wherein the second The top surface area of the protective layer in contact with the third protective layer is greater than or equal to the bottom surface area of the second protective layer in contact with the first protective layer. The method for fabricating an organic electroluminescence display device according to claim 1, further comprising forming a pixel defining layer having a pixel region on the first substrate, and the pixel region is accommodated Electroluminescent layer. The method for fabricating an organic electroluminescence display device according to claim 1, wherein the forming the second protective layer is performed by inkjet printing or screen printing. The method for fabricating an organic electroluminescence display device according to claim 3, further comprising performing a curing step after forming the second protective layer. The method for fabricating an organic electroluminescence display device according to claim 4, wherein the viscosity of the second protective layer ranges from 1 centipoise to 1000 centipoise before the curing step. The method for fabricating an organic electroluminescence display device according to claim 2, further comprising: correspondingly forming a color filter layer on the first substrate below the pixel region, and sealing a second substrate An upper surface of the light emitting unit is formed on a surface of the first substrate. The method for fabricating an organic electroluminescence display device according to claim 2, further comprising forming a reflective layer on the first substrate below the pixel region, and sealing one of the color filter layers The second substrate is on the first substrate, wherein the color filter layer corresponds to the reflective layer. An organic electroluminescence display device comprising: a first substrate having at least one thin film transistor; a light emitting unit formed on the first substrate; a first protective layer formed on the light emitting unit; a second protective layer is formed on the first protective layer, wherein the first protective layer has a recess above the light emitting unit, and the second protective layer is disposed in the recess, the second protective layer The surface is coplanar with the upper surface of the first protective layer; and a third protective layer is formed on the second protective layer and contacts the first protective layer, wherein the second protective layer is in contact with the third protective layer The top surface area is greater than or equal to the bottom surface area of the second protective layer in contact with the first protective layer. The organic electroluminescent display device of claim 8, wherein the first protective layer and the third protective layer comprise cerium oxide, aluminum oxide, titanium dioxide, indium oxide, tin oxide, indium tin oxide, and nitriding. Aluminum, tantalum nitride, niobium carbide or niobium oxynitride. The organic electroluminescent display device of claim 8, wherein the second protective layer comprises an organic material. The organic electroluminescent display device of claim 8, wherein the second protective layer comprises an epoxy resin or an acrylic polymer-containing material. The organic electroluminescent display device of claim 8, wherein the second protective layer comprises a color photoresist. The organic electroluminescent display device of claim 8, wherein a distance between the top edge of the second protective layer and the third protective layer is greater than or equal to the second protective layer and the first protection The distance between the bottom edges of the layer contacts. The organic electroluminescent display device of claim 8, further comprising a pixel defining layer having a pixel region formed on the first substrate, wherein the pixel region houses an organic electro-optical Light-emitting layer. The organic electroluminescent display device of claim 14, wherein the second protective layer has a bottom width greater than or equal to a bottom width of the organic electroluminescent layer. The organic electroluminescent display device of claim 14, further comprising: a color filter layer, the first base formed under the pixel region And a second substrate sealed over the surface of the first substrate on which the light emitting unit is formed. The organic electroluminescent display device of claim 14, further comprising: a second substrate correspondingly disposed on a surface of the first substrate on which the light emitting unit is formed; a color filter layer formed And corresponding to the pixel region on the second substrate; and a reflective layer disposed on the first substrate under the pixel region.